1. Field of the Invention
The present invention relates to a broadband RF connector interconnect for multilayer electronic packages, and more particularly to impedance matching to provide improved broadband performance in ceramic multilayer packages requiring brazed connectors.
2. History of the Prior Art
It is known in the art to provide a coaxial transition arrangement including a broadband RF connector interconnect for multilayer electronic packages. Such arrangements are commonly used in, for example, radar systems having an electronic package with a transmit/receive module and antenna feed network for the transmitter.
In such arrangements, it is difficult to achieve broadband high frequency RF performance from a coaxial connector transition to a transmission line structure within a multilayer package. It is impossible to compensate the impedance mismatch within the connector by using impedance matching structures inside the package alone. Attempts to compensate connector transition by reducing the braze pad for the pin connection leads to high-risk manufacturing and connector reliability.
Various different arrangements have been tried in an attempt to provide impedance matching and thereby broadband performance in coaxial transition arrangements. Such an arrangement is shown in U.S. Pat. No. 3,745,488 of Rogers. This patent describes a disk 76 and a ring 78 which are moveable within a coaxial structure to achieve impedance matching. However, such structure is relatively complex and not readily adapted to coaxial transition arrangements which couple a coaxial cable to a multilayer package so that impedance matching is achieved with minimum modification. Similar comments apply to U.S. Pat. No. 6,028,497 of Allen in which the impedance of a coaxial transmission line is adjusted by adjusting the width and shape of a pin and the inner diameter of a washer-shaped end of a shroud.